Mendelian randomization analysis explores the causal relationship between cathepsins and osteoarthritis

Mendelian randomization analysis explores the causal relationship between cathepsins and osteoarthritis | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Mendelian randomization analysis explores the causal relationship between cathepsins and osteoarthritis Yifeng Huang, Haoshaqiang Zhang, Xinru Xie, Zhigang Wang This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4426486/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Osteoarthritis, a primary etiology of joint dysfunction, entails a multifaceted pathogenesis. Cathepsins, cysteine proteases localized within lysosomes, exert pivotal roles across diverse physiological and pathological contexts. Although observational inquiries suggest an interrelation between cathepsins and osteoarthritis, the etiological nexus remains elusive. Employing Mendelian randomization analysis, this investigation endeavors to elucidate this causal nexus. Univariate Mendelian randomization analysis reveals a plausible augmentation in osteoarthritis risk concomitant with a decline in cathepsin S levels. Conversely, reverse Mendelian randomization analysis posits that osteoarthritis might precipitate a reduction in cathepsin L2 levels. Multivariable analysis, encompassing 9 proteases as covariates, demonstrates a potential collaborative effect between elevated cathepsin F levels and diminished cathepsin S levels, thereby accentuating osteoarthritis risk. In summation, cathepsin S emerges as a prospective biomarker for osteoarthritis, conferring implications for diagnostic and therapeutic paradigms targeting this ailment. Mendelian randomization cathepsins osteoarthritis genome-wide association causal relationship Figures Figure 1 Figure 2 Introduction Osteoarthritis (OA) is a common chronic disease characterized by the degenerative changes of articular cartilage, inflammatory responses, and the interplay of factors such as cell apoptosis ( 1 ). With the ongoing trend of population aging, the incidence of OA is on the rise ( 2 ). Clinically, OA manifests as joint pain, swelling, and restricted movement, significantly impacting patients' quality of life ( 3 ). The pathogenesis of OA involves multiple factors ( 4 ), including joint cartilage damage, the action of inflammatory cytokines, and cell apoptosis. Among these, aberrant activity of cathepsins are considered one of the key factors leading to cartilage injury ( 5 ). Cathepsins play a critical role in maintaining cellular homeostasis, and their dysregulated activity is closely associated with various diseases ( 6 – 8 ). Cathepsin S, as one of them, plays a significant role in regulating inflammatory responses ( 9 ). Genomic studies have revealed the role of genetic factors in OA ( 10 , 11 ). Mendelian randomization (MR) is an effective research method that can infer the causal impact of exposure factors on disease outcomes ( 12 ). In this study, we utilized the MR approach to investigate the causal influence of cathepsins on OA by analyzing genetic variants associated with cathepsins levels. Methods Instrumental Variables In this study, we employed Mendelian randomization (MR) methodology to explore the potential impact of nine cathepsins on osteoarthritis (OA). The data for the study were sourced from the INTERVAL study, which comprises data from 3,301 individuals of European descent ( 13 ). All participants had provided informed consent, and the study had obtained approval from the National Research Ethics Service (11/EE/0538). We selected instruments for MR analysis that met specific criteria. These criteria included an R2 value less than 0.001 for linkage disequilibrium (LD) measured within a 10,000 kb window between instruments and a p-value below the genome-wide significance threshold determined in the respective studies (set at 5×10^−6). These criteria were established considering the limitations of sample size, ensuring the relevance of the selected instruments to cathepsins levels while mitigating confounding factors. The data for this study are available at https://gask.mrcieu.ac.uk . Genetic Associations of SNPs with Osteoarthritis Summary data for osteoarthritis were obtained from TRICL ( https://www.ebi.ac.uk/gwas ), comprising GWAS analysis results for 39,515 cases and 445,083 controls. These data include estimates of odds ratios (ORs) and standard deviations of instrumental SNPs. All participants provided informed consent, and the relevant studies underwent ethical review and approval by respective institutional review boards. Statistical Analysis and Reproducibility In this study, Mendelian randomization (MR) was utilized, employing genetic variants as instrumental variables to ascertain whether exposure has a causal impact on the outcome. Effective instrumental variables must meet three core criteria: first, they should be strongly associated with the exposure. Second, SNPs should not be associated with characteristics that may confound the relationship between exposure and outcome. Lastly, aside from the exposure, certain variants should not be associated with the outcome through alternative pathways. When the latter two assumptions are violated, SNPs are considered to exhibit horizontal pleiotropy. In this MR study, the IVW (Inverse Variance Weighted) method was primarily employed to estimate the overall effect size ( 14 ). In essence, the influence of each genetic variant on the risk of the studied disease is weighted by its effect on the exposure values in the Wald ratio method utilized in the IVW approach. Subsequently, individual MR estimates are combined using the random-effects inverse variance method to obtain an overall pooled effect. Supplementary methods, including MR-Egger ( 15 )and weighted median ( 16 ), were also employed to validate the robustness of MR results. Briefly, MR-Egger regression is a weighted linear regression that weights SNP-outcome associations by SNP-exposure associations, while the weighted median method calculates the median by weighting individual MR estimates. The TwoSampleMR package in R software was utilized to perform IVW, MR-Egger, and weighted median methods [16]( 17 ). Various sensitivity analyses and statistical tests were conducted to assess the validity of assumptions. Firstly, Cochran's Q test was employed to assess heterogeneity among SNPs. Lack of heterogeneity, indicated by a p-value greater than 0.05, permits analysis using a fixed-effects model. When significant heterogeneity exists among SNPs, analysis is conducted using a random-effects model ( 18 ). MR-PRESSO global test and MR-Egger intercept were employed to identify outliers and horizontal pleiotropy effects ( 19 ). MR-Egger intercept estimates the average pleiotropy effect, while the slope generates robust pleiotropy-adjusted MR estimates. When horizontal pleiotropy is significant, MR-PRESSO outlier test is used for correction. Finally, omission analysis was performed to identify SNPs that may have potential extreme influences on estimates, further evaluating the reliability of results. All these sensitivity analyses, along with related global tests, outlier tests, and distortion tests, were conducted using the MR-PRESSO package in R software ( 19 ). Multivariable Mendelian Randomization is an extension of standard univariable MR, utilized for analyzing the causal effects of multiple cathepsins on osteoarthritis and estimating the direct causal effects of each exposure in a single analysis. This study employed the "MendelianRandomization" package ( 18 ). The methodology allows for consideration of the effects of multiple cathepsins. Additionally, reverse MR analyses were conducted, with osteoarthritis as the exposure and cathepsins as the outcome, to assess reverse causal relationships and demonstrate bidirectional causality ( 20 ). In these reverse MR analyses, the same GWAS dataset as mentioned above was utilized, selecting instrumental variables for osteoarthritis, and utilizing cathepsins abundance levels from the INTERVAL study as outcomes. All statistical analyses were conducted using R software version 4.3.1. Results Causal relationships between different types of cathepsins and osteoarthritis. To assess the impact of different cathepsins on the risk of osteoarthritis, a two-sample Mendelian Randomization (MR) analysis was initially conducted for nine types of cathepsins Cathepsin B, E, F, G, H, L2, O, S, and Z) and osteoarthritis risk. Univariable MR analysis results showed that high levels of cathepsin S reduced the risk of osteoarthritis (Inverse Variance Weighted IVW: P = 3.50×10^-4, OR = 0.997, 95% CI = 0.995 ~ 0.999). The MR-Egger method (P = 4.14×10^-4, OR = 0.994, 95% CI = 0.993 ~ 0.998) and Weighted median method (P = 2.83×10^-5, OR = 0.995, 95% CI = 0.992 ~ 0.997) further confirmed these consistent significant correlations. In Supplementary Fig. 1, neither the MR-Egger nor the MR-PRESSO global tests provided evidence of directional pleiotropy for any of these causal relationships. However, the IVW method did not reveal any causal relationships between other types of cathepsin and overall osteoarthritis. Table 1 Assessment of the causal relationship between tissue proteinase L2 and osteoarthritis using reverse MR analysis Cathepsin L2 SNPs OR (95%CI) p_value Inverse variance weighted 48 0.071(0.0058–0.8802) 0.0394 MR Egger 48 0.018(1.87×10 − 5 -17.6479) 0.2593 Weighted median 48 0.413(0.0101–16.8489) 0.6402 Simple mode 48 15.58(0.0040-60737.2294) 0.5182 Weighted mode 48 24.13(0.0049-119923.8226) 0.4671 To explore the possibility of reverse causal relationships, reverse MR analyses were conducted. The results in Table 1 indicate that cathepsin S lacks a reverse causal relationship with osteoarthritis. However, reverse MR analysis provided evidence that osteoarthritis is inversely associated with cathepsin L2 levels (IVW: P = 0.0394, OR = 0.0714, 95% CI = 0.0057 ~ 0.8802); there were no signs of directional pleiotropy in the P-values for MR-Egger and Weighted median tests (0.2593 and 0.6402, respectively). There was no evidence supporting causal relationships between osteoarthritis and various other types of cathepsins. Furthermore, multivariable MR was conducted to assess the genetic susceptibility involving multiple cathepsins and the risk of osteoarthritis. The results in Fig. 2 showed that even after adjusting for other types of cathepsin, a decrease in cathepsin S levels remained correlated with the risk of osteoarthritis (IVW: P = 0.0263, OR = 0.9979, 95% CI = 0.9960 ~ 0.9998); whereas an increase in cathepsin F levels was correlated with the risk of osteoarthritis (IVW: P = 0.0295, OR = 01.0031, 95% CI = 1.003 ~ 1.0058). Discussion The development of osteoarthritis is an exceedingly complex process in which protein degradation plays a crucial role. Amidst this complexity, cathepsins play pivotal roles. In this study, we systematically analyzed the causal relationships between nine different cathepsins and the risk of osteoarthritis using genetic tools, employing MR analysis from large-scale genetic consortia to discern their associations. Through integrating the results of univariable and multivariable analyses, we draw the following conclusions: cathepsin S plays an important protective role in the occurrence and progression of osteoarthritis, with no observed reverse causal relationship. Multivariable analysis further indicates that the decrease in cathepsin S levels, along with the increase in cathepsin F levels, collectively contribute to the development of osteoarthritis. In this study, the decrease in cathepsin S was found to be associated with a reduced risk of osteoarthritis, with consistent results across methods including the IVW method, which did not show a reverse causal relationship. However, observational studies suggest that an increase in cathepsin S is positively correlated with the severity of osteoarthritis inflammation ( 21 ), a correlation not supported by MR analysis. Multivariable Mendelian Randomization analysis helps mitigate potential biases inherent in traditional observational studies, allowing for comprehensive consideration of confounders, interactions, and the effects of multiple genetic variants. The results of multivariable analysis suggest that cathepsin S may jointly influence the development of osteoarthritis with cathepsin F. This conclusion may arise from univariable analysis insufficiently considering other confounders and interactions between factors, thereby enhancing statistical power and reducing false positive rates. cathepsin S is a cysteine protease, active in low pH environments, typically operating within lysosomes ( 9 ). Its primary function involves digesting damaged or unnecessary proteins within lysosomes, released by macrophages at inflammatory sites, effectively hydrolyzing aggregated polysaccharides. While osteoarthritis is generally considered a non-inflammatory condition, the role of cathepsin S in it remains incompletely understood. Studies by Caglič et al ( 22 )suggest that cathepsin S can also be expressed and secreted in non-immune chondrocytes, though direct biological relevance to high molecular weight substrates in cartilage (such as aggregated proteoglycans and collagen) has not been directly demonstrated. Research by Rauner et al. ( 23 )found that knockout of the CTSS gene in mouse experiments resulted in increased bone turnover, decreased bone density, and thinner trabeculae. Additionally, molecular inhibition of CTSS has been shown to induce autophagy-associated apoptotic mechanisms in tumor cells, leading to cell death. Inhibition of CTSS results in the attenuation of the PI3K/Akt/mTOR/p70s6K pathway and activation of the JNK signaling pathway, both of which can induce DNA damage and ultimately cell death through upregulation of reactive oxygen species via xanthine oxidase ( 24 ). Results from Chwastek et al. ( 25 ) further indicate that upregulation of cathepsin S is beneficial for inflamed synovial tissue due to its anti-fibrotic properties, particularly in cases of synovial fibrosis-induced joint stiffness. Additionally, Yao et al. ( 26 ) found that cathepsin S regulates renal extracellular matrix (ECM) fibrosis by modulating the TGF-β/SMAD pathway. Collectively, these findings underscore the importance of cathepsin S in osteoarthritis, strengthen evidence of causal links between them, and suggest it as a potential therapeutic target, providing robust support for future treatment strategies. Recent research indicates that cathepsin F plays a crucial role in apoptosis and lysosomal protein degradation. cathepsin F is abundantly present in specific sites of the epidermis and dermis in elderly individuals, particularly in senescent cells where its expression is significantly higher than in proliferating cells ( 27 ). It has been found that cathepsin F can regulate the expression of multiple genes in the apoptosis pathway, such as enhancing the expression of pro-apoptotic gene Bid, while suppressing the expression of anti-apoptotic genes Bcl-2 and C-IAPs ( 28 ). In stem cell research, inhibition of cathepsin F demonstrates anti-apoptotic effects ( 29 ). Another study found that silencing the expression of cathepsin F enhances the growth of gastric cancer cells and reduces the level of cell apoptosis, thus promoting cancer progression; conversely, upregulation of cathepsin F expression has an inhibitory effect on cancer progression ( 30 , 31 ). cathepsin F may be involved in the degradation process of articular cartilage in osteoarthritis. In osteoarthritis, articular cartilage is affected by various inflammatory and degenerative changes, including an increase in the activity of cathepsins ( 32 ). These cathepsins can degrade the matrix components of articular cartilage, such as collagen and proteoglycans, leading to cartilage destruction and degradation. Interestingly, recent research suggests that an increase in cathepsin F may increase the risk of osteoarthritis, a finding not previously reported by researchers. Therefore, the relationship between cathepsin F and osteoarthritis may be more complex, requiring further research to elucidate potential mechanisms of action. cathepsin V (Cathepsin V, CTSV), also known as cathepsin L2, was first discovered by Santamaria et al. in 1998 ( 33 ). It shares 78% homology with cathepsin L (CTSL) and is encoded by the CTSV gene ( 34 ). CTSV belongs to the cysteine protease endopeptidase family and exhibits optimal physiological activity at a pH of 4. This enzyme has various physiological roles, including MHC class II-restricted antigen presentation, corneal neovascularization, and involvement in vascular diseases and cancer. Studies have shown that increased expression of CTSV can induce endothelial cell senescence through the ALDH1A2-AKT/ERK1/2-P21 pathway ( 35 ). Furthermore, CTSV has been found to be an effective elastase, participating in extracellular matrix (ECM) remodeling, and its decreased activity may mediate ECM remodeling and imbalance in lung tissue homeostasis( 36 ).In inflammation regulation, cathepsin also play crucial roles. Inflammatory response is a key process in the development of osteoarthritis, where cathepsins can influence many inflammation-related signaling pathways and cytokine release. Although research on CTSV in osteoarthritis is not yet sufficient, further investigation may contribute to a better understanding of the role of this cathepsins in the disease. These research findings may elucidate mechanisms of articular cartilage destruction and provide clues for developing new strategies to treat osteoarthritis. Conclusions Preliminary genetic evidence from this study suggests that low levels of cathepsin S and high levels of cathepsin F may increase the risk of developing osteoarthritis. Additionally, osteoarthritis may play an important role in regulating the expression of cathepsin V. By further understanding the role of cathepsins in osteoarthritis, scientists and clinical practitioners can explore new therapeutic strategies, search for drugs that can regulate cathepsins activity, develop new treatment methods to slow disease progression, or identify new biomarkers for diagnosing and monitoring osteoarthritis. Declarations Ethics approval and consent to participate Ethics approval is presented in the mentioned GWAS studies. Consent for publication Not applicable Availability of data and material The raw data analyzed during the current study were available in public databases https://www.ebi.ac.uk/gwas. Competing interests The authors declare no competing interests Funding This work was supported by grant from Natural Science Foundation of Xinjiang Uygur Autonomous Region(2021D01C137). Authors' contributions H.Z and Y.H conceived and designed the experiment; Y.H and X.X ran the analysis and verified the underlying data; Y.H and Z.W wrote the original manuscript. H.Z.involved in data interpretation. All authors have read and approved the final version of the manuscript. Acknowledgments The authors thank the studies or consortiums cited and included in this analysis for providing public datasets. References Norimatsu K, Nakanishi K, Ijuin T, Otsuka S, Takada S, Tani A, et al. Effects of low-intensity exercise on spontaneously developed knee osteoarthritis in male senescence-accelerated mouse prone 8. Arthritis Res Ther. 2023;25:168. Zhao J, Zeng L, Pan J, Liang G, Huang H, Yang W, et al. Comparisons of the Efficacy and Safety of Total Knee Arthroplasty by Different Surgical Approaches: A Systematic Review and Network Meta-analysis. Orthop Surg. 2022;14(3):472–85. Liu Y, Jing J, Yu H, Zhang J, Cao Q, Zhang X, et al. Expression profiles of long non-coding RNAs in the cartilage of patients with knee osteoarthritis and normal individuals. Exp Ther Med. 2021;21(4):365. Glyn-Jones S, Palmer AJR, Agricola R, Price AJ, Vincent TL, Weinans H, et al. Osteoarthr Lancet. 2015;386(9991):376–87. Yasuda Y, Kaleta J, Brömme D. The role of cathepsins in osteoporosis and arthritis: Rationale for the design of new therapeutics. Adv Drug Delivery Rev. 2005;57(7):973–93. Anes E, Pires D, Mandal M, Azevedo-Pereira JM. Spatial localization of cathepsins: Implications in immune activation and resolution during infections. Front Immunol. 2022;13:955407. Tran AP, Silver J. Cathepsins in neuronal plasticity. Neural Regen Res. 2020;16(1):26–35. Somoza JR, Palmer JT, Ho JD. The Crystal Structure of Human Cathepsin F and Its Implications for the Development of Novel Immunomodulators. J Mol Biol. 2002;322(3):559–68. Smyth P, Sasiwachirangkul J, Williams R, Scott CJ. Cathepsin S (CTSS) activity in health and disease - A treasure trove of untapped clinical potential. Mol Aspects Med. 2022;88:101106. Brennan P, Hainaut P, Boffetta P. Genetics of lung-cancer susceptibility. Lancet Oncol. 2011;12(4):399–408. Sekula P, Del Greco MF, Pattaro C, Köttgen A. Mendelian Randomization as an Approach to Assess Causality Using Observational Data. J Am Soc Nephrol. 2016;27(11):3253–65. Burgess S, Davey Smith G, Davies NM, Dudbridge F, Gill D, Glymour MM, et al. Guidelines for performing Mendelian randomization investigations: update for summer 2023. Wellcome Open Res. 2019;4:186. Sun BB, Maranville JC, Peters JE, Stacey D, Staley JR, Blackshaw J, et al. Genomic atlas of the human plasma proteome. Nature. 2018;558(7708):73–9. Burgess S, Butterworth A, Thompson SG. Mendelian randomization analysis with multiple genetic variants using summarized data. Genet Epidemiol. 2013;37(7):658–65. Bowden J, Davey Smith G, Burgess S. Mendelian randomization with invalid instruments: effect estimation and bias detection through Egger regression. Int J Epidemiol. 2015;44(2):512–25. Bowden J, Davey Smith G, Haycock PC, Burgess S. Consistent Estimation in Mendelian Randomization with Some Invalid Instruments Using a Weighted Median Estimator. Genet Epidemiol. 2016;40(4):304–14. Hemani G, Zheng J, Elsworth B, Wade KH, Haberland V, Baird D, et al. The MR-Base platform supports systematic causal inference across the human phenome. Elife. 2018;7:e34408. Yavorska OO, Burgess S. MendelianRandomization: an R package for performing Mendelian randomization analyses using summarized data. Int J Epidemiol. 2017;46(6):1734–9. Verbanck M, Chen CY, Neale B, Do R. Detection of widespread horizontal pleiotropy in causal relationships inferred from Mendelian randomization between complex traits and diseases. Nat Genet. 2018;50(5):693–8. Relton CL, Davey Smith G. Two-step epigenetic Mendelian randomization: a strategy for establishing the causal role of epigenetic processes in pathways to disease. Int J Epidemiol. 2012;41(1):161–76. Caglič D, Repnik U, Jedeszko C, Kosec G, Miniejew C, Kindermann M, et al. The proinflammatory cytokines interleukin-1α and tumor necrosis factor α promote the expression and secretion of proteolytically active cathepsin S from human chondrocytes. Biol Chem. 2013;394(2):307–16. Caglič D, Repnik U, Jedeszko C, Kosec G, Miniejew C, Kindermann M, et al. The proinflammatory cytokines interleukin-1α and tumor necrosis factor α promote the expression and secretion of proteolytically active cathepsin S from human chondrocytes. Biol Chem. 2013;394(2):307–16. Rauner M, Föger-Samwald U, Kurz MF, Brünner-Kubath C, Schamall D, Kapfenberger A, et al. Cathepsin S controls adipocytic and osteoblastic differentiation, bone turnover, and bone microarchitecture. Bone. 2014;64:281–7. Zhang L, Wang H, Xu J, Zhu J, Ding K. Inhibition of cathepsin S induces autophagy and apoptosis in human glioblastoma cell lines through ROS-mediated PI3K/AKT/mTOR/p70S6K and JNK signaling pathways. Toxicol Lett. 2014;228(3):248–59. Chwastek J, Kędziora M, Borczyk M, Korostyński M, Starowicz K. Inflammation-Driven Secretion Potential Is Upregulated in Osteoarthritic Fibroblast-Like Synoviocytes. Int J Mol Sci. 2022;23(19):11817. Yao X, Cheng F, Yu W, Rao T, Li W, Zhao S, et al. Cathepsin S regulates renal fibrosis in mouse models of mild and severe hydronephrosis. Mol Med Rep. 2019;20(1):141–50. Takaya K, Asou T, Kishi K. Cathepsin F is a potential marker for senescent human skin fibroblasts and keratinocytes associated with skin aging. GeroScience. 2022;45(1):427–37. Yao C, Zhou Y, Wang H, Deng F, Chen Y, Zhu X, et al. Adipose-derived stem cells alleviate radiation-induced dermatitis by suppressing apoptosis and downregulating cathepsin F expression. Stem Cell Res Ther. 2021;12:447. Ginnetti AT, Paone DV, Nanda KK, Li J, Busuek M, Johnson SA, et al. Lead optimization of cathepsin K inhibitors for the treatment of Osteoarthritis. Bioorg Med Chem Lett. 2022;74:128927. Ji C, Zhao Y, Kou YW, Shao H, Guo L, Bao CH, et al. Cathepsin F Knockdown Induces Proliferation and Inhibits Apoptosis in Gastric Cancer Cells. Oncol Res. 2018;26(1):83–93. Zheng L, Cao J, Liu L, Xu H, Chen L, Kang L, et al. Long noncoding RNA LINC00982 upregulates CTSF expression to inhibit gastric cancer progression via the transcription factor HEY1. Am J Physiology-Gastrointestinal Liver Physiol. 2021;320(5):G816–28. Ginnetti AT, Paone DV, Nanda KK, Li J, Busuek M, Johnson SA, et al. Lead optimization of cathepsin K inhibitors for the treatment of Osteoarthritis. Bioorg Med Chem Lett. 2022;74:128927. Lecaille F, Chazeirat T, Saidi A, Lalmanach G, Cathepsin V. Molecular characteristics and significance in health and disease. Mol Aspects Med. 2022;88:101086. Du X, Chen NLH, Wong A, Craik CS, Brömme D. Elastin degradation by cathepsin V requires two exosites. J Biol Chem. 2013;288(48):34871–81. Li C, Liu Z, Chen M, Zhang L, Shi R, Zhong H. Critical Role of Cathepsin L/V in Regulating Endothelial Cell Senescence. Biology (Basel). 2022;12(1):42. Chazeirat T, Denamur S, Bojarski KK, Andrault PM, Sizaret D, Zhang F, et al. The abnormal accumulation of heparan sulfate in patients with mucopolysaccharidosis prevents the elastolytic activity of cathepsin V. Carbohydr Polym. 2021;253:117261. Supplementary Figures Supplementary Figure 1 is not available with this version Additional Declarations No competing interests reported. Supplementary Files Multivariableanalysis.xlsx UnivariableMRanalysisresults.xlsx reverseMendelianrandomizationanalysis.xlsx Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-4426486","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":307515039,"identity":"e75af439-ae68-48c3-89ff-fed9d6b6c5d8","order_by":0,"name":"Yifeng Huang","email":"","orcid":"","institution":"People's Hospital of Xinjiang Uygur Autonomous Region","correspondingAuthor":false,"prefix":"","firstName":"Yifeng","middleName":"","lastName":"Huang","suffix":""},{"id":307515040,"identity":"049e16c0-489f-4d35-9143-3dedd51ac202","order_by":1,"name":"Haoshaqiang Zhang","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAyUlEQVRIiWNgGAWjYBACNmb+jw8+VPzjkWdmPkCcFj52BmPDGWcOyBi2syUQp0WOn8FMmrflgA3DeR4DYh3GkGw4s+EOD2Mzz8cbbxjs5HQbCGs5+ODjjmc87My8my3nMCQbmx0gqIWx2XDmGWagLbzbpHkYDiRuI6yFmU2at42Zh+EwzzNitbCBtBwGaWEjVgsPMzCQ03gMm9mMLecYEOEX+f4zjMCotLGX5z/88MabCjs5glpQgASxUYOshVQdo2AUjIJRMCIAAEfaOtv7hY0wAAAAAElFTkSuQmCC","orcid":"","institution":"People's Hospital of Xinjiang Uygur Autonomous Region","correspondingAuthor":true,"prefix":"","firstName":"Haoshaqiang","middleName":"","lastName":"Zhang","suffix":""},{"id":307515041,"identity":"45c381da-001a-4156-a73c-aa511df7ee81","order_by":2,"name":"Xinru Xie","email":"","orcid":"","institution":"the First Affiliated Hospital of Xinjiang Medical University","correspondingAuthor":false,"prefix":"","firstName":"Xinru","middleName":"","lastName":"Xie","suffix":""},{"id":307515042,"identity":"8612f27e-0d55-4c7f-ae04-e8add00213bd","order_by":3,"name":"Zhigang Wang","email":"","orcid":"","institution":"People's Hospital of Xinjiang Uygur Autonomous Region","correspondingAuthor":false,"prefix":"","firstName":"Zhigang","middleName":"","lastName":"Wang","suffix":""}],"badges":[],"createdAt":"2024-05-15 16:36:14","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4426486/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4426486/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":57502403,"identity":"3e2db054-fc56-4982-b635-c4aa50d8d152","added_by":"auto","created_at":"2024-05-31 14:14:04","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":433654,"visible":true,"origin":"","legend":"\u003cp\u003eForest plots of cathepsins on osteoarthritis. The forward causality were marked red in the figure. Inverse variance weighting; Weighted median; MR-Egger; Simple mode; Weighted mode; OR, odds ratio; CI, confidence interval\u003c/p\u003e","description":"","filename":"Fig1.png","url":"https://assets-eu.researchsquare.com/files/rs-4426486/v1/73b3c67dc77ca1ffb66a7988.png"},{"id":57502402,"identity":"029c6aa7-168f-401c-bbfe-32ef488688f2","added_by":"auto","created_at":"2024-05-31 14:14:04","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":228229,"visible":true,"origin":"","legend":"\u003cp\u003eForest plot of multivariable Mendelian randomization inversevariance weighted analysis for nine cathepsins and osteoarthritis. The inverse-variance weighted method was employed to investigate the causal relationships between nine cathepsins (cathepsin B, E, F, G, H, L2, O, S, and Z) and osteoarthritis. (Highlighted in red are statistically significant results, and error bars indicate 95% confidence intervals).\u003c/p\u003e","description":"","filename":"Fig2.png","url":"https://assets-eu.researchsquare.com/files/rs-4426486/v1/261e80a2cbb8d43b77070dab.png"},{"id":58290584,"identity":"e72c80e5-fcc0-486b-a3b0-0cc713449062","added_by":"auto","created_at":"2024-06-13 13:29:25","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":919811,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4426486/v1/6b151d23-beba-4faf-9ffd-869fe7fa93b5.pdf"},{"id":57502399,"identity":"1f7d3937-f747-482e-b6c0-125420d2c2f0","added_by":"auto","created_at":"2024-05-31 14:14:03","extension":"xlsx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":9913,"visible":true,"origin":"","legend":"","description":"","filename":"Multivariableanalysis.xlsx","url":"https://assets-eu.researchsquare.com/files/rs-4426486/v1/a3e2ea408e867169c5fcc9cf.xlsx"},{"id":57502898,"identity":"4e40b6ec-39e3-4651-b114-f577b7296867","added_by":"auto","created_at":"2024-05-31 14:22:03","extension":"xlsx","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":12002,"visible":true,"origin":"","legend":"","description":"","filename":"UnivariableMRanalysisresults.xlsx","url":"https://assets-eu.researchsquare.com/files/rs-4426486/v1/e70691a24ff15ca5f790a4a4.xlsx"},{"id":57502401,"identity":"1b7946c7-20e1-43fa-9c0b-fe71af94f06d","added_by":"auto","created_at":"2024-05-31 14:14:04","extension":"xlsx","order_by":3,"title":"","display":"","copyAsset":false,"role":"supplement","size":12176,"visible":true,"origin":"","legend":"","description":"","filename":"reverseMendelianrandomizationanalysis.xlsx","url":"https://assets-eu.researchsquare.com/files/rs-4426486/v1/ebde479c3a9c212a464b0c64.xlsx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Mendelian randomization analysis explores the causal relationship between cathepsins and osteoarthritis","fulltext":[{"header":"Introduction","content":"\u003cp\u003eOsteoarthritis (OA) is a common chronic disease characterized by the degenerative changes of articular cartilage, inflammatory responses, and the interplay of factors such as cell apoptosis (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e). With the ongoing trend of population aging, the incidence of OA is on the rise (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e). Clinically, OA manifests as joint pain, swelling, and restricted movement, significantly impacting patients' quality of life (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe pathogenesis of OA involves multiple factors (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e), including joint cartilage damage, the action of inflammatory cytokines, and cell apoptosis. Among these, aberrant activity of cathepsins are considered one of the key factors leading to cartilage injury (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e). Cathepsins play a critical role in maintaining cellular homeostasis, and their dysregulated activity is closely associated with various diseases (\u003cspan additionalcitationids=\"CR7\" citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e). Cathepsin S, as one of them, plays a significant role in regulating inflammatory responses (\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eGenomic studies have revealed the role of genetic factors in OA (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e). Mendelian randomization (MR) is an effective research method that can infer the causal impact of exposure factors on disease outcomes (\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e). In this study, we utilized the MR approach to investigate the causal influence of cathepsins on OA by analyzing genetic variants associated with cathepsins levels.\u003c/p\u003e"},{"header":"Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eInstrumental Variables\u003c/h2\u003e \u003cp\u003eIn this study, we employed Mendelian randomization (MR) methodology to explore the potential impact of nine cathepsins on osteoarthritis (OA). The data for the study were sourced from the INTERVAL study, which comprises data from 3,301 individuals of European descent (\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e). All participants had provided informed consent, and the study had obtained approval from the National Research Ethics Service (11/EE/0538). We selected instruments for MR analysis that met specific criteria. These criteria included an R2 value less than 0.001 for linkage disequilibrium (LD) measured within a 10,000 kb window between instruments and a p-value below the genome-wide significance threshold determined in the respective studies (set at 5\u0026times;10^\u0026minus;6). These criteria were established considering the limitations of sample size, ensuring the relevance of the selected instruments to cathepsins levels while mitigating confounding factors. The data for this study are available at \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://gask.mrcieu.ac.uk\u003c/span\u003e\u003cspan address=\"https://gask.mrcieu.ac.uk\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003eGenetic Associations of SNPs with Osteoarthritis\u003c/h2\u003e \u003cp\u003eSummary data for osteoarthritis were obtained from TRICL (\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.ebi.ac.uk/gwas\u003c/span\u003e\u003cspan address=\"https://www.ebi.ac.uk/gwas\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e), comprising GWAS analysis results for 39,515 cases and 445,083 controls. These data include estimates of odds ratios (ORs) and standard deviations of instrumental SNPs. All participants provided informed consent, and the relevant studies underwent ethical review and approval by respective institutional review boards.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eStatistical Analysis and Reproducibility\u003c/h2\u003e \u003cp\u003eIn this study, Mendelian randomization (MR) was utilized, employing genetic variants as instrumental variables to ascertain whether exposure has a causal impact on the outcome. Effective instrumental variables must meet three core criteria: first, they should be strongly associated with the exposure. Second, SNPs should not be associated with characteristics that may confound the relationship between exposure and outcome. Lastly, aside from the exposure, certain variants should not be associated with the outcome through alternative pathways. When the latter two assumptions are violated, SNPs are considered to exhibit horizontal pleiotropy.\u003c/p\u003e \u003cp\u003eIn this MR study, the IVW (Inverse Variance Weighted) method was primarily employed to estimate the overall effect size (\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e). In essence, the influence of each genetic variant on the risk of the studied disease is weighted by its effect on the exposure values in the Wald ratio method utilized in the IVW approach. Subsequently, individual MR estimates are combined using the random-effects inverse variance method to obtain an overall pooled effect. Supplementary methods, including MR-Egger (\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e)and weighted median (\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e), were also employed to validate the robustness of MR results. Briefly, MR-Egger regression is a weighted linear regression that weights SNP-outcome associations by SNP-exposure associations, while the weighted median method calculates the median by weighting individual MR estimates. The TwoSampleMR package in R software was utilized to perform IVW, MR-Egger, and weighted median methods [16](\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eVarious sensitivity analyses and statistical tests were conducted to assess the validity of assumptions. Firstly, Cochran's Q test was employed to assess heterogeneity among SNPs. Lack of heterogeneity, indicated by a p-value greater than 0.05, permits analysis using a fixed-effects model. When significant heterogeneity exists among SNPs, analysis is conducted using a random-effects model (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e). MR-PRESSO global test and MR-Egger intercept were employed to identify outliers and horizontal pleiotropy effects (\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e). MR-Egger intercept estimates the average pleiotropy effect, while the slope generates robust pleiotropy-adjusted MR estimates. When horizontal pleiotropy is significant, MR-PRESSO outlier test is used for correction. Finally, omission analysis was performed to identify SNPs that may have potential extreme influences on estimates, further evaluating the reliability of results. All these sensitivity analyses, along with related global tests, outlier tests, and distortion tests, were conducted using the MR-PRESSO package in R software (\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eMultivariable Mendelian Randomization is an extension of standard univariable MR, utilized for analyzing the causal effects of multiple cathepsins on osteoarthritis and estimating the direct causal effects of each exposure in a single analysis. This study employed the \"MendelianRandomization\" package (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e). The methodology allows for consideration of the effects of multiple cathepsins. Additionally, reverse MR analyses were conducted, with osteoarthritis as the exposure and cathepsins as the outcome, to assess reverse causal relationships and demonstrate bidirectional causality (\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e). In these reverse MR analyses, the same GWAS dataset as mentioned above was utilized, selecting instrumental variables for osteoarthritis, and utilizing cathepsins abundance levels from the INTERVAL study as outcomes. All statistical analyses were conducted using R software version 4.3.1.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eCausal relationships between different types of cathepsins and osteoarthritis.\u003c/p\u003e \u003cp\u003eTo assess the impact of different cathepsins on the risk of osteoarthritis, a two-sample Mendelian Randomization (MR) analysis was initially conducted for nine types of cathepsins Cathepsin B, E, F, G, H, L2, O, S, and Z) and osteoarthritis risk. Univariable MR analysis results showed that high levels of cathepsin S reduced the risk of osteoarthritis (Inverse Variance Weighted IVW: P\u0026thinsp;=\u0026thinsp;3.50\u0026times;10^-4, OR\u0026thinsp;=\u0026thinsp;0.997, 95% CI\u0026thinsp;=\u0026thinsp;0.995\u0026thinsp;~\u0026thinsp;0.999). The MR-Egger method (P\u0026thinsp;=\u0026thinsp;4.14\u0026times;10^-4, OR\u0026thinsp;=\u0026thinsp;0.994, 95% CI\u0026thinsp;=\u0026thinsp;0.993\u0026thinsp;~\u0026thinsp;0.998) and Weighted median method (P\u0026thinsp;=\u0026thinsp;2.83\u0026times;10^-5, OR\u0026thinsp;=\u0026thinsp;0.995, 95% CI\u0026thinsp;=\u0026thinsp;0.992\u0026thinsp;~\u0026thinsp;0.997) further confirmed these consistent significant correlations. In Supplementary Fig.\u0026nbsp;1, neither the MR-Egger nor the MR-PRESSO global tests provided evidence of directional pleiotropy for any of these causal relationships. However, the IVW method did not reveal any causal relationships between other types of cathepsin and overall osteoarthritis.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eAssessment of the causal relationship between tissue proteinase L2 and osteoarthritis using reverse MR analysis\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCathepsin L2\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eSNPs\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eOR (95%CI)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003ep_value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eInverse variance weighted\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e48\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.071(0.0058\u0026ndash;0.8802)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.0394\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eMR Egger\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e48\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.018(1.87\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;5\u003c/sup\u003e-17.6479)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.2593\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eWeighted median\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e48\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.413(0.0101\u0026ndash;16.8489)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.6402\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eSimple mode\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e48\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e15.58(0.0040-60737.2294)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.5182\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cb\u003eWeighted mode\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e48\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e24.13(0.0049-119923.8226)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.4671\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eTo explore the possibility of reverse causal relationships, reverse MR analyses were conducted. The results in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e indicate that cathepsin S lacks a reverse causal relationship with osteoarthritis. However, reverse MR analysis provided evidence that osteoarthritis is inversely associated with cathepsin L2 levels (IVW: P\u0026thinsp;=\u0026thinsp;0.0394, OR\u0026thinsp;=\u0026thinsp;0.0714, 95% CI\u0026thinsp;=\u0026thinsp;0.0057\u0026thinsp;~\u0026thinsp;0.8802); there were no signs of directional pleiotropy in the P-values for MR-Egger and Weighted median tests (0.2593 and 0.6402, respectively). There was no evidence supporting causal relationships between osteoarthritis and various other types of cathepsins.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eFurthermore, multivariable MR was conducted to assess the genetic susceptibility involving multiple cathepsins and the risk of osteoarthritis. The results in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e showed that even after adjusting for other types of cathepsin, a decrease in cathepsin S levels remained correlated with the risk of osteoarthritis (IVW: P\u0026thinsp;=\u0026thinsp;0.0263, OR\u0026thinsp;=\u0026thinsp;0.9979, 95% CI\u0026thinsp;=\u0026thinsp;0.9960\u0026thinsp;~\u0026thinsp;0.9998); whereas an increase in cathepsin F levels was correlated with the risk of osteoarthritis (IVW: P\u0026thinsp;=\u0026thinsp;0.0295, OR\u0026thinsp;=\u0026thinsp;01.0031, 95% CI\u0026thinsp;=\u0026thinsp;1.003\u0026thinsp;~\u0026thinsp;1.0058).\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe development of osteoarthritis is an exceedingly complex process in which protein degradation plays a crucial role. Amidst this complexity, cathepsins play pivotal roles. In this study, we systematically analyzed the causal relationships between nine different cathepsins and the risk of osteoarthritis using genetic tools, employing MR analysis from large-scale genetic consortia to discern their associations. Through integrating the results of univariable and multivariable analyses, we draw the following conclusions: cathepsin S plays an important protective role in the occurrence and progression of osteoarthritis, with no observed reverse causal relationship. Multivariable analysis further indicates that the decrease in cathepsin S levels, along with the increase in cathepsin F levels, collectively contribute to the development of osteoarthritis.\u003c/p\u003e \u003cp\u003eIn this study, the decrease in cathepsin S was found to be associated with a reduced risk of osteoarthritis, with consistent results across methods including the IVW method, which did not show a reverse causal relationship. However, observational studies suggest that an increase in cathepsin S is positively correlated with the severity of osteoarthritis inflammation (\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e), a correlation not supported by MR analysis. Multivariable Mendelian Randomization analysis helps mitigate potential biases inherent in traditional observational studies, allowing for comprehensive consideration of confounders, interactions, and the effects of multiple genetic variants. The results of multivariable analysis suggest that cathepsin S may jointly influence the development of osteoarthritis with cathepsin F. This conclusion may arise from univariable analysis insufficiently considering other confounders and interactions between factors, thereby enhancing statistical power and reducing false positive rates.\u003c/p\u003e \u003cp\u003ecathepsin S is a cysteine protease, active in low pH environments, typically operating within lysosomes (\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e). Its primary function involves digesting damaged or unnecessary proteins within lysosomes, released by macrophages at inflammatory sites, effectively hydrolyzing aggregated polysaccharides. While osteoarthritis is generally considered a non-inflammatory condition, the role of cathepsin S in it remains incompletely understood. Studies by Caglič et al (\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e)suggest that cathepsin S can also be expressed and secreted in non-immune chondrocytes, though direct biological relevance to high molecular weight substrates in cartilage (such as aggregated proteoglycans and collagen) has not been directly demonstrated. Research by Rauner et al. (\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e)found that knockout of the CTSS gene in mouse experiments resulted in increased bone turnover, decreased bone density, and thinner trabeculae. Additionally, molecular inhibition of CTSS has been shown to induce autophagy-associated apoptotic mechanisms in tumor cells, leading to cell death. Inhibition of CTSS results in the attenuation of the PI3K/Akt/mTOR/p70s6K pathway and activation of the JNK signaling pathway, both of which can induce DNA damage and ultimately cell death through upregulation of reactive oxygen species via xanthine oxidase (\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e). Results from Chwastek et al. (\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e) further indicate that upregulation of cathepsin S is beneficial for inflamed synovial tissue due to its anti-fibrotic properties, particularly in cases of synovial fibrosis-induced joint stiffness. Additionally, Yao et al. (\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e) found that cathepsin S regulates renal extracellular matrix (ECM) fibrosis by modulating the TGF-β/SMAD pathway. Collectively, these findings underscore the importance of cathepsin S in osteoarthritis, strengthen evidence of causal links between them, and suggest it as a potential therapeutic target, providing robust support for future treatment strategies.\u003c/p\u003e \u003cp\u003eRecent research indicates that cathepsin F plays a crucial role in apoptosis and lysosomal protein degradation. cathepsin F is abundantly present in specific sites of the epidermis and dermis in elderly individuals, particularly in senescent cells where its expression is significantly higher than in proliferating cells (\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e). It has been found that cathepsin F can regulate the expression of multiple genes in the apoptosis pathway, such as enhancing the expression of pro-apoptotic gene Bid, while suppressing the expression of anti-apoptotic genes Bcl-2 and C-IAPs (\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e). In stem cell research, inhibition of cathepsin F demonstrates anti-apoptotic effects (\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e). Another study found that silencing the expression of cathepsin F enhances the growth of gastric cancer cells and reduces the level of cell apoptosis, thus promoting cancer progression; conversely, upregulation of cathepsin F expression has an inhibitory effect on cancer progression (\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e, \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e). cathepsin F may be involved in the degradation process of articular cartilage in osteoarthritis. In osteoarthritis, articular cartilage is affected by various inflammatory and degenerative changes, including an increase in the activity of cathepsins (\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e). These cathepsins can degrade the matrix components of articular cartilage, such as collagen and proteoglycans, leading to cartilage destruction and degradation. Interestingly, recent research suggests that an increase in cathepsin F may increase the risk of osteoarthritis, a finding not previously reported by researchers. Therefore, the relationship between cathepsin F and osteoarthritis may be more complex, requiring further research to elucidate potential mechanisms of action.\u003c/p\u003e \u003cp\u003ecathepsin V (Cathepsin V, CTSV), also known as cathepsin L2, was first discovered by Santamaria et al. in 1998 (\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e). It shares 78% homology with cathepsin L (CTSL) and is encoded by the CTSV gene (\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e). CTSV belongs to the cysteine protease endopeptidase family and exhibits optimal physiological activity at a pH of 4. This enzyme has various physiological roles, including MHC class II-restricted antigen presentation, corneal neovascularization, and involvement in vascular diseases and cancer. Studies have shown that increased expression of CTSV can induce endothelial cell senescence through the ALDH1A2-AKT/ERK1/2-P21 pathway (\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e). Furthermore, CTSV has been found to be an effective elastase, participating in extracellular matrix (ECM) remodeling, and its decreased activity may mediate ECM remodeling and imbalance in lung tissue homeostasis(\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e).In inflammation regulation, cathepsin also play crucial roles. Inflammatory response is a key process in the development of osteoarthritis, where cathepsins can influence many inflammation-related signaling pathways and cytokine release. Although research on CTSV in osteoarthritis is not yet sufficient, further investigation may contribute to a better understanding of the role of this cathepsins in the disease. These research findings may elucidate mechanisms of articular cartilage destruction and provide clues for developing new strategies to treat osteoarthritis.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003ePreliminary genetic evidence from this study suggests that low levels of cathepsin S and high levels of cathepsin F may increase the risk of developing osteoarthritis. Additionally, osteoarthritis may play an important role in regulating the expression of cathepsin V. By further understanding the role of cathepsins in osteoarthritis, scientists and clinical practitioners can explore new therapeutic strategies, search for drugs that can regulate cathepsins activity, develop new treatment methods to slow disease progression, or identify new biomarkers for diagnosing and monitoring osteoarthritis.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eEthics approval is presented in the mentioned GWAS studies.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and material\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe raw data analyzed during the current study were available in public databases \u0026nbsp;https://www.ebi.ac.uk/gwas. \u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no competing interests\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis work was supported by grant from Natural Science Foundation of Xinjiang Uygur Autonomous Region(2021D01C137).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026apos; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eH.Z and Y.H conceived and designed the experiment; Y.H and X.X ran the analysis and verified the underlying data; Y.H and Z.W wrote the original manuscript. H.Z.involved in data interpretation. All authors have read and approved the final version of the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgments\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors thank the studies or consortiums cited and included in this analysis for providing public datasets.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eNorimatsu K, Nakanishi K, Ijuin T, Otsuka S, Takada S, Tani A, et al. Effects of low-intensity exercise on spontaneously developed knee osteoarthritis in male senescence-accelerated mouse prone 8. Arthritis Res Ther. 2023;25:168.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhao J, Zeng L, Pan J, Liang G, Huang H, Yang W, et al. Comparisons of the Efficacy and Safety of Total Knee Arthroplasty by Different Surgical Approaches: A Systematic Review and Network Meta-analysis. Orthop Surg. 2022;14(3):472\u0026ndash;85.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLiu Y, Jing J, Yu H, Zhang J, Cao Q, Zhang X, et al. Expression profiles of long non-coding RNAs in the cartilage of patients with knee osteoarthritis and normal individuals. Exp Ther Med. 2021;21(4):365.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGlyn-Jones S, Palmer AJR, Agricola R, Price AJ, Vincent TL, Weinans H, et al. Osteoarthr Lancet. 2015;386(9991):376\u0026ndash;87.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYasuda Y, Kaleta J, Br\u0026ouml;mme D. The role of cathepsins in osteoporosis and arthritis: Rationale for the design of new therapeutics. Adv Drug Delivery Rev. 2005;57(7):973\u0026ndash;93.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAnes E, Pires D, Mandal M, Azevedo-Pereira JM. Spatial localization of cathepsins: Implications in immune activation and resolution during infections. Front Immunol. 2022;13:955407.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTran AP, Silver J. Cathepsins in neuronal plasticity. Neural Regen Res. 2020;16(1):26\u0026ndash;35.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSomoza JR, Palmer JT, Ho JD. The Crystal Structure of Human Cathepsin F and Its Implications for the Development of Novel Immunomodulators. J Mol Biol. 2002;322(3):559\u0026ndash;68.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSmyth P, Sasiwachirangkul J, Williams R, Scott CJ. Cathepsin S (CTSS) activity in health and disease - A treasure trove of untapped clinical potential. Mol Aspects Med. 2022;88:101106.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBrennan P, Hainaut P, Boffetta P. Genetics of lung-cancer susceptibility. Lancet Oncol. 2011;12(4):399\u0026ndash;408.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSekula P, Del Greco MF, Pattaro C, K\u0026ouml;ttgen A. Mendelian Randomization as an Approach to Assess Causality Using Observational Data. J Am Soc Nephrol. 2016;27(11):3253\u0026ndash;65.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBurgess S, Davey Smith G, Davies NM, Dudbridge F, Gill D, Glymour MM, et al. Guidelines for performing Mendelian randomization investigations: update for summer 2023. Wellcome Open Res. 2019;4:186.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSun BB, Maranville JC, Peters JE, Stacey D, Staley JR, Blackshaw J, et al. Genomic atlas of the human plasma proteome. Nature. 2018;558(7708):73\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBurgess S, Butterworth A, Thompson SG. Mendelian randomization analysis with multiple genetic variants using summarized data. Genet Epidemiol. 2013;37(7):658\u0026ndash;65.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBowden J, Davey Smith G, Burgess S. Mendelian randomization with invalid instruments: effect estimation and bias detection through Egger regression. Int J Epidemiol. 2015;44(2):512\u0026ndash;25.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBowden J, Davey Smith G, Haycock PC, Burgess S. Consistent Estimation in Mendelian Randomization with Some Invalid Instruments Using a Weighted Median Estimator. Genet Epidemiol. 2016;40(4):304\u0026ndash;14.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHemani G, Zheng J, Elsworth B, Wade KH, Haberland V, Baird D, et al. The MR-Base platform supports systematic causal inference across the human phenome. Elife. 2018;7:e34408.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYavorska OO, Burgess S. MendelianRandomization: an R package for performing Mendelian randomization analyses using summarized data. Int J Epidemiol. 2017;46(6):1734\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVerbanck M, Chen CY, Neale B, Do R. Detection of widespread horizontal pleiotropy in causal relationships inferred from Mendelian randomization between complex traits and diseases. Nat Genet. 2018;50(5):693\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRelton CL, Davey Smith G. Two-step epigenetic Mendelian randomization: a strategy for establishing the causal role of epigenetic processes in pathways to disease. Int J Epidemiol. 2012;41(1):161\u0026ndash;76.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCaglič D, Repnik U, Jedeszko C, Kosec G, Miniejew C, Kindermann M, et al. The proinflammatory cytokines interleukin-1α and tumor necrosis factor α promote the expression and secretion of proteolytically active cathepsin S from human chondrocytes. Biol Chem. 2013;394(2):307\u0026ndash;16.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCaglič D, Repnik U, Jedeszko C, Kosec G, Miniejew C, Kindermann M, et al. The proinflammatory cytokines interleukin-1α and tumor necrosis factor α promote the expression and secretion of proteolytically active cathepsin S from human chondrocytes. Biol Chem. 2013;394(2):307\u0026ndash;16.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRauner M, F\u0026ouml;ger-Samwald U, Kurz MF, Br\u0026uuml;nner-Kubath C, Schamall D, Kapfenberger A, et al. Cathepsin S controls adipocytic and osteoblastic differentiation, bone turnover, and bone microarchitecture. Bone. 2014;64:281\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhang L, Wang H, Xu J, Zhu J, Ding K. Inhibition of cathepsin S induces autophagy and apoptosis in human glioblastoma cell lines through ROS-mediated PI3K/AKT/mTOR/p70S6K and JNK signaling pathways. Toxicol Lett. 2014;228(3):248\u0026ndash;59.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChwastek J, Kędziora M, Borczyk M, Korostyński M, Starowicz K. Inflammation-Driven Secretion Potential Is Upregulated in Osteoarthritic Fibroblast-Like Synoviocytes. Int J Mol Sci. 2022;23(19):11817.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYao X, Cheng F, Yu W, Rao T, Li W, Zhao S, et al. Cathepsin S regulates renal fibrosis in mouse models of mild and severe hydronephrosis. Mol Med Rep. 2019;20(1):141\u0026ndash;50.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTakaya K, Asou T, Kishi K. Cathepsin F is a potential marker for senescent human skin fibroblasts and keratinocytes associated with skin aging. GeroScience. 2022;45(1):427\u0026ndash;37.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYao C, Zhou Y, Wang H, Deng F, Chen Y, Zhu X, et al. Adipose-derived stem cells alleviate radiation-induced dermatitis by suppressing apoptosis and downregulating cathepsin F expression. Stem Cell Res Ther. 2021;12:447.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGinnetti AT, Paone DV, Nanda KK, Li J, Busuek M, Johnson SA, et al. Lead optimization of cathepsin K inhibitors for the treatment of Osteoarthritis. Bioorg Med Chem Lett. 2022;74:128927.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJi C, Zhao Y, Kou YW, Shao H, Guo L, Bao CH, et al. Cathepsin F Knockdown Induces Proliferation and Inhibits Apoptosis in Gastric Cancer Cells. Oncol Res. 2018;26(1):83\u0026ndash;93.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZheng L, Cao J, Liu L, Xu H, Chen L, Kang L, et al. Long noncoding RNA LINC00982 upregulates CTSF expression to inhibit gastric cancer progression via the transcription factor HEY1. Am J Physiology-Gastrointestinal Liver Physiol. 2021;320(5):G816\u0026ndash;28.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGinnetti AT, Paone DV, Nanda KK, Li J, Busuek M, Johnson SA, et al. Lead optimization of cathepsin K inhibitors for the treatment of Osteoarthritis. Bioorg Med Chem Lett. 2022;74:128927.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLecaille F, Chazeirat T, Saidi A, Lalmanach G, Cathepsin V. Molecular characteristics and significance in health and disease. Mol Aspects Med. 2022;88:101086.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDu X, Chen NLH, Wong A, Craik CS, Br\u0026ouml;mme D. Elastin degradation by cathepsin V requires two exosites. J Biol Chem. 2013;288(48):34871\u0026ndash;81.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLi C, Liu Z, Chen M, Zhang L, Shi R, Zhong H. Critical Role of Cathepsin L/V in Regulating Endothelial Cell Senescence. Biology (Basel). 2022;12(1):42.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChazeirat T, Denamur S, Bojarski KK, Andrault PM, Sizaret D, Zhang F, et al. The abnormal accumulation of heparan sulfate in patients with mucopolysaccharidosis prevents the elastolytic activity of cathepsin V. Carbohydr Polym. 2021;253:117261.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"},{"header":"Supplementary Figures","content":"\u003cp\u003eSupplementary Figure 1 is not available with this version\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Mendelian randomization, cathepsins, osteoarthritis, genome-wide association, causal relationship","lastPublishedDoi":"10.21203/rs.3.rs-4426486/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4426486/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eOsteoarthritis, a primary etiology of joint dysfunction, entails a multifaceted pathogenesis. Cathepsins, cysteine proteases localized within lysosomes, exert pivotal roles across diverse physiological and pathological contexts. Although observational inquiries suggest an interrelation between cathepsins and osteoarthritis, the etiological nexus remains elusive. Employing Mendelian randomization analysis, this investigation endeavors to elucidate this causal nexus. Univariate Mendelian randomization analysis reveals a plausible augmentation in osteoarthritis risk concomitant with a decline in cathepsin S levels. Conversely, reverse Mendelian randomization analysis posits that osteoarthritis might precipitate a reduction in cathepsin L2 levels. Multivariable analysis, encompassing 9 proteases as covariates, demonstrates a potential collaborative effect between elevated cathepsin F levels and diminished cathepsin S levels, thereby accentuating osteoarthritis risk. In summation, cathepsin S emerges as a prospective biomarker for osteoarthritis, conferring implications for diagnostic and therapeutic paradigms targeting this ailment.\u003c/p\u003e","manuscriptTitle":"Mendelian randomization analysis explores the causal relationship between cathepsins and osteoarthritis","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-05-31 14:13:59","doi":"10.21203/rs.3.rs-4426486/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"bd36b4e6-fbbb-4d4a-80e9-d6218dab14d6","owner":[],"postedDate":"May 31st, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2024-06-13T13:21:18+00:00","versionOfRecord":[],"versionCreatedAt":"2024-05-31 14:13:59","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-4426486","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4426486","identity":"rs-4426486","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}